Compact Balun Filter with High Isolation by Using Phase Inverter

With the rapid development of modern network and wireless communication technology,various network equipment and electronic products can communicate through the wireless access network, all of this must depend on the critical RF module and RF components. Now days so many electronic equipments in various fields are developing toward the miniaturization, multi-function and high performance direction. In order to realize the miniaturization of wireless systems and electronic products, occupy a larger volume of RF and microwave components the need to achieve miniaturization. In this thesis, a novel enhanced balun bandpass filter with extremely small size and high isolation is demonstrated utilizing the combination of diagonally shorted coupled lines and parallel end shorted coupled lines both with shunt lumped capacitors and parallel-strip phase inverter. The coupled lines with shunt lumped capacitors can be used to largely reduce the required electrical length of transmission line. And the parallel-strip phase inverter is utilized to realize the balanced matching and isolation. Comparing with the typical Marchand Balun, it not only has excellent performance but also has no need to add any other resistive network between the outputs.Nomenclature II Abstract III CHAPTER 1 Introduction 1 1.1 Background and Introduction of Balun 1 1.2 Organization of the Thesis 5 CHAPTER 2 Isolation Balun Design Theory 6 2.1 Ordinary Balun Design 6 2.2 Isolation and Matching Network of Balun Outputs 8 2.3 Size Reduction Method 10 2.3.1 Diagonally Shorted Coupled Lines with Lumped Capacitors 10 2.3.2 Parallel End Shorted Coupled Lines with Lumped Capacitors 13 2.4 DSPSL Phase Inverter 16 2.5 New Structure for Isolation Miniaturized Balun Filter 19 CHAPTER 3 Simulation, Fabrication and Measurement 25 3.1 Circuit Simulating by ADS and Analysis 25 3.2 Full-Wave EM Simulation by HFSS and Optimization 28 3.3 Fabrication and Measurement 32 Chapter 4 Conclusion 36 References 37 Acknowledgement 4

Design Methodology for Six-Port Equal/Unequal Quadrature and Rat-Race Couplers With Balanced and Unbalanced Ports Terminated by Arbitrary Resistances

For the first time, the 6-port quadrature and rat-race couplers with balanced-unbalanced-hybrid ports are proposed. The corresponding design methodology is presented, which is capable of designing the proposed couplers with arbitrary power divisions and terminated resistances. In this paper, four types including quadrature and rat-race couplers are fully analyzed, covering all the application configurations of the balanced/unbalanced ports. Besides, the design equations are rigorously derived, with the final design procedures presented. Eventually, prototypes of the four coupler types are fabricated and experimentally measured. The final results sufficiently validate the proposed methodology

The miniaturization and bandwidth enhancement of printed circuit balun designs for wireless applications

Master'sMASTER OF ENGINEERIN

Direct integration of push-pull amplifier and aperture coupled antenna

The work described in this thesis concerns the integration of push-pull class B amplifier and antenna modules. Push-pull class B is well-known with its fruitful advantages of using differential feeding technique, resulting in low distortion, reasonably high efficiency and high output power. Meanwhile, the antenna module in this work is adapted from the aperture-coupled antenna structure due to its degree of freedom to control the variables which provide the best possible topology that could be realised in system on chip or system in package. More generally, the variables allow good coverage of the Smith Chart so that a wide range of odd-mode matching requirements could be met, for different devices and bias condition of a given transistor. The approach also offers additional filtering up to 3rd harmonic in that it comprises identical harmonic traps on both sides of the aperture using resonant stubs to form bandstop filters, which reduce the ripples at the output waveforms, giving them a significant advantage of neat and tight integration of a push-pull transmitting amplifier

Dual-band Microwave Components And Their Applications

In general, Dual-Band technology enables microwave components to work at two different frequencies. This thesis introduces novel dual-band microwave components and their applications. Chapter 2 presents a novel compact dual-band balun (converting unbalanced signals to balanced ones). The ratio between two working frequencies is analyzed. A novel compact microstrip crossover (letting two lines to cross each other with very high isolation) and its dual-band application is the subject of chapter 3. A dual-frequency cloak based on lumped LC-circuits is introduced in chapter 4. In chapter 5, a dual-band RF device to detect dielectric constant changes of liquids in polydimethylsiloxane (PDMS) microfluidic channels has been presented. Such a device is very sensitive, and it has significantly improved the stability. Finally, conclusion of this thesis and future works are given in chapter 6

Compliance verification methodology for renewable generation integration. Application to island power grids

261 p.This thesis proposes a new methodology to validate the integration of renewable generation to install in island power grids. In weak power grids, the penetration of non-synchronous power generation can be challenging. Furthermore, system operators often impose strict technical requirements. In order to streamline grid code compliance verification, this thesis presents a simulation based procedure focused on most critical rules in isolated power grids: Frequency Ride-Through, Low Voltage Ride-Through and voltage and current unbalance. The methodology presented in this thesis proposes a generic and reduced grid model as equivalent system suitable for both simulating the static and dynamic performance of a selected power system for interconnection and design purposes, and for verifying the compliance of aforementioned technical requirements. Depending on the disturbance to be represented and on sensitivity studies of the model parameters, the generic grid model must be then particularised, in order to obtain a particular grid model. Finally, the grid model has to be parameterised based on grid characteristics and grid code limits, resulting into a parameterised grid model. In the present thesis, the methodology is applied to three study cases, where the installation of a renewable power plant is under study: a medium size island grid, Terceira island in the Açores and Fuerteventura-Lanzarote system. The numerical application to these three study cases backs the validity of the methodology proposed in the present thesis

3-D antenna array analysis using the induced EMF method

The effect of mutual coupling between elements plays a crucial role to the performance of the antenna arrays. The radiation patterns of antenna arrays will be altered by the coupling effect from the adjacent elements thus reducing the accuracy and resolution in direction finding application. This research developed and validated the novel 3-D Algorithm to calculate the far-field pattern of dipole arrays arranged in three dimensions and in any configuration (both in straight and slanted position). The effect of mutual coupling has been accounted using the Induced EMF method. The computation is performed on 2x2 parallel dipoles and 12 dipoles arranged at the edge of a cube. The results are validated with other electromagnetic techniques such as Method of Moment (MoM) and Finite Difference Time-Domain (FDTD). Then, a 2x2 dipole array is chosen for beam steering and experiment validation due to its ease of implementation and feeding network. The array optimisation to control the pattern is performed using a genetic algorithm. The far-field pattern computed using the 3-D algorithm might be less accurate than other 3-D electromagnetic techniques but its array optimisation is faster and efficient. The simulation and measurement results are in good agreement with each other confirmed the validity of the 3-D algorithm

SiGe-based broadband and high suppression frequency doubler ICs for wireless communications

制度:新 ; 報告番号:甲3419号 ; 学位の種類:博士(工学) ; 授与年月日:2011/9/15 ; 早大学位記番号:新574

Passive and active components development for broadband applications

Recently, GaN HEMTs have been proven to have numerous physical properties, resulting in transistors with greatly increased power densities when compared to the other well-established FET technologies. This advancement spurred research and product development towards power-band applications that require both high power and high efficiency over the wide band. Even though the use of multiple narrow band PAs covering the whole band has invariably led to better performance in terms of efficiency and noise, there is an associated increase in cost and in the insertion loss of the switches used to toggle between the different operating bands. The goal, now, of the new technology is to replace the multiple narrow band PAs with one broadband PA that has a comparable efficiency performance. In our study here, we have investigated a variety of wide band power amplifiers, including class AB PAs and their implementation in distributed and feedback PAs.Additionally, our investigation has included switching-mode PAs as they are well-known for achieving a relatively high efficiency. Besides having a higher efficiency, they are also less susceptible to parameter variations and could impose a lower thermal stress on the transistors than the conventional-mode PAs. With GaN HEMTs, we have demonstrated: a higher than 37 dBm output power and a more than 30% drain efficiency over 0.02 to 3 GHz for the distributed power amplifier; a higher than 30 dBm output power with more than a 22% drain efficiency over 0.1 to 5 GHz for the feedback amplifier; and at least a 43 dBm output power with a higher than 63% drain efficiency over 0.05 to 0.55 GHz for the class D PA. In many communication applications, however, achieving both high efficiency and linearity in the PA design is required. Therefore, in our research, we have evaluated several linearization and efficiency enhancement techniques.We selected the LInear amplification with Nonlinear Components (LINC) approach. Highly efficient combiner and novel efficiency enhancement techniques like the power recycling combiner and adaptive bias LINC schemes have been successfully developed and verified to achieve a combined high efficiency with a relatively high linearity